1. Field of the Invention
This invention relates to a multiple color painting apparatus for painting, e.g., car bodywork.
2. Description of the Related Art
A multiple color painting apparatus is disclosed in Japanese Patent Laid-Open Publication No. HEI 7-108198. In this painting apparatus, paint is fed from multiple color-changing valves to a gear pump by one intake passage, whereafter the paint is fed by one delivery passage (supply pipe) from the gear pump to a paint gun and sprayed out through a nozzle hole.
However, with this painting apparatus, because the paint is carried by the single intake passage and the single delivery passage, when changing for example from white paint to red paint, it is necessary to wash the intake passage and the delivery passage with a washing liquid consisting of thinner. Consequently there has been the problem that because the length of passage that must be washed with thinner is long, a large quantity of thinner is required and the washing time also becomes long.
As means for solving this problem, for example an `electrostatic painting machine` disclosed in Japanese Patent Laid-Open Publication No. HEI 7-185405 has been proposed. As shown in FIG. 1 of that publication, in this electrostatic painting machine, capillary nozzles are provided for a number of colors in a rotary spray head of a paint gun, and paints of different colors are carried separately by these nozzles. With this electrostatic painting machine, because a dedicated passage is used for each of the paints of different colors, the capillary nozzles do not have to be washed when changing between paint colors.
However, with this electrostatic painting machine, because multiple capillary nozzles are extended to the tip of the paint gun and a gear pump is provided for each of the multiple capillary nozzles, the construction of the painting machine is complicated and the painting machine is large.
It is therefore an object of the present invention to provide a painting apparatus with which the paint changing time is short and which is simple and compact.